Blue smoke

[george kornreich]

My low-time engine, Volvo Penta MD22L, is producing quite a bit of blue smoke on startup, which about goes away as it warms up. The engine runs beautifully, though. I am using 15W-40 oil. The fuel has been in the tank quite a long time, as we sail a lot but motor very little and a tank of fuel lasts forever. The fuel as seen through the Racor bowl (which itself it colored yellow/orange) appears dark amber in color, but it transparant with no opacity seen. Is this a matter of oil too thin on the startup, getting by the rings, etc (I've been told I should run straight 40 weight oil in this warm climate) or could it have something to do with aging fuel (or just maybe the engine has a problem ?Thanks

 

[G. Richard Stidger]

You are not alone

George,Welcome to the club. I have a 1997 Volvo MD22L in my 40.5. Upon delivery I noticed the blue smoke and queried my dealer. The answer was to keep an eye on it and get some hours rolled on.At the end of the first year, I had about 150 hours and the same amount of smoke. Went to the Volvo service rep shop, had injectors checked - basically OK, some light scoring, but no conclusive evidence of a problem.I pushed the issue with my dealer and Hunter. My concern was that there was a latent defect with the engine- maybe a bad injection pump, bad cam, who knows. I didn't want to get 5-10 years down the road and have a major bill, or take a huge hit upon selling.The bottom line: My dealer and Hunter stood behind me (actually in FRONT) and convinced Volvo to replace the engine under warrantee and to extend the far-too-short warrantee of 1 year to a full second year. BTW, Volvo replaced at least 2 of these engines for Hunter owners that year.Now I have another engine. I have about 250-275 hours on the new engine. It still smokes at startup and even at running speed there is a very light trail of blue smoke. Overall, not a great improvement over the original engine. The Volvo factory rep claims that is normal and typical for that particular engine.I have tried Cetane improvers with no real smoke decrease. The same fuel runs clean as a whistle in my Westerbeke genset in the same boat. I guess it really is normal, but I would rather not have it.Other than the smoke, the engine runs flawlessly.I can't say enough good things about my dealer, Sailing Specialties in West Mystic, CT, and the no-nonsense people at the Hunter factory. They all went 120% for me on this one.I will be very interested to hear others opinions and corrective steps taken.Rich

 

[george kornreich]

Thanks, Rich

I appreciated your reply very much, as hearing that this is "normal" relieves my concern considerably. Your comment about the genset interested mealso, as I have a Kohler genset, same fuel supply (like your setup) and no smoke there either. Volvo (local authorized mechanic) describes this as a difference in the operating cylinder temps of a small vs a larger engine (take that or leave it... wouldn't bet the farm on his opinion). He also thinkd the smoke is from some shrinkage of the valve guide seals from not running the engine enough, and says to take her out and run full bore for a couple of hours. I'm game to try this, this weekend.

 

[Rich Stidger]

WOT for 10 minutes only

The Volvo factory rep that did the sea trials on my new engine told me that I should run the engine at 400rpm less than WOT all the time unless I was in a speed constrained area. That would be about 2600 rpm. At that speed, he said I could run 24/7.He also recommended running at WOT for 10 minutes every time I go out. The purpose is two-fold. First it helps keep the engine clean of deposits. Second, it assures you that your engine is always capable of full performance should you ever need it. Any problem with the engine, bad fuel, or linkage problems will show up as not being able to pull full rpm's.Makes sense to me. I do my 10 minute 'burn' on my way back in.BTW, I forgot to tell you that I do not see any significant consumption of engine oil. I use straight 30W diesel rated oil. Thus the 'blue smoke' is due to fuel not being completely burned.Rich

 

[Mickey McHugh]

Another member of the club.

I also have a Volvo MD22L in my 1997 H40.5 and I also noticed some smoke during cold startups but it quickly goes away. I thought it was unburned fuel because the engine was cold. I always preheat for 7 to 10 seconds before turning over a cold engine. Also I make sure that the water heater has been on before starting because it effects how soon the engine warms up. I found this out while we were in Long Beach because of the cold Pacific water and the 30-amp service. Since we could not use both the Heating Ventilation & Air Conditioning (HVAC) systems and the water heater at the same time, a couple of times I started the engine with a cold slug of water in the water heater. Talk about a blue cloud! Having the water heater on makes a BIG difference. I only have a couple of winter months in Texas where I see more smoke than normal.And about the Volvo rep who thinks the smoke is from some shrinkage of the valve guide seals from not running the engine enough, and says to take her out and run full bore for a couple of hours. He might be right. I usually run between 2000 and 2200 RPM. Recently, during a power run down the ICW to Matagora, we wanted to get in before dark as I ran 2600 for five hours (before running out of fuel – but that’s another story). Since then, I have noticed very little smoke. Of course it is a HOT summer so I will wait until January to know for sure. But I can tell it made a difference. I like everything about my Volvo, even the blue smoke that means it’s getting a ‘pre-lube’ during a cold start.